Editing Fundamentals of Nursing (section)

== Vital signs ==

Typical adult reference ranges:
* '''Temperature:''' about 36.5 to 37.5 degrees Celsius (97.7 to 99.5 degrees Fahrenheit) orally.
* '''Pulse:''' 60 to 100 beats per minute.
* '''Respirations:''' 12 to 20 breaths per minute.
* '''Blood pressure:''' normal is a systolic below 120 and a diastolic below 80 millimeters of mercury. Elevated is systolic 120 to 129 with diastolic below 80; stage 1 hypertension is 130 to 139 systolic or 80 to 89 diastolic; stage 2 is 140 or higher systolic or 90 or higher diastolic.
* '''Oxygen saturation:''' generally 95 to 100 percent on room air. Patients with chronic carbon dioxide retention may have an individualized lower target, often around 88 to 92 percent.
* '''Pain:''' documented as the fifth vital sign in many settings, though it is a symptom rather than a physiologic measurement.

Measurement technique:
* '''Temperature routes.''' Rectal readings approximate core temperature most closely but are contraindicated with rectal surgery, diarrhea, neutropenia, and clotting disorders. Wait 15 to 30 minutes after hot or cold liquids, smoking, or chewing gum before an oral reading. Tympanic and temporal artery readings are fast but technique dependent. Axillary readings are the least accurate. Document the route, because the route changes the interpretation.
* '''Pulse.''' The apical pulse is auscultated at the fifth intercostal space at the left midclavicular line. Count for a full minute if the rhythm is irregular or the patient is an infant. Assess the apical pulse for one full minute before giving digoxin and hold the dose for an adult apical rate below 60. A pulse deficit is the difference between simultaneously counted apical and radial rates and indicates ineffective contractions.
* '''Respirations.''' Count without telling the patient, ideally while appearing to take the pulse, because awareness alters the pattern.
* '''Blood pressure.''' The cuff bladder width should be about 40 percent of the arm circumference and the length about 80 percent. A cuff that is too narrow or applied over clothing gives a falsely high reading; a cuff that is too wide gives a falsely low reading. Support the arm at heart level; an arm below heart level reads falsely high. Avoid the arm with a dialysis access, mastectomy with lymph node dissection, intravenous infusion, or injury.
* '''Orthostatic vital signs.''' Measure supine, then sitting, then standing, waiting one to three minutes between positions. A drop of 20 millimeters of mercury or more in systolic pressure, or 10 or more in diastolic pressure, or symptoms of dizziness, is a positive finding and a fall risk.

Interpretation notes: fever raises the pulse and respiratory rate. A widening pulse pressure with bradycardia and irregular respirations suggests rising intracranial pressure and is an emergency. Pulse oximetry is unreliable with poor perfusion, hypothermia, vasoconstriction, motion, nail polish, and carbon monoxide poisoning, where the reading can be falsely normal. Always compare to the patient's own baseline and treat the patient, not the number.